Imaging lens

ABSTRACT

An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; a seventh lens; an eighth lens; and a ninth lens having negative refractive power, arranged in this order from an object side to an image plane side. The imaging lens has a total of nine lenses. The first lens is formed in a shape so that a surface thereof on the image plane side has an aspherical shape. The ninth lens is formed in a shape so that a surface thereof on the image plane side has an aspherical shape.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of a prior application Ser. No.16/722,032, filed on Dec. 20, 2019, allowed.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to an imaging lens for forming an image ofan object on an imaging element such as a CCD sensor and a CMOS sensor.In particular, the present invention relates to an imaging lens suitablefor mounting in a relatively small camera such as a camera to be builtin a portable device, e.g., a cellular phone and a portable informationterminal, a digital still camera, a security camera, an onboard camera,and a network camera.

Currently, so-called “smartphones”, i.e., multifunctional cellularphones which can run various application software as well as a voicecall function, have been more widely used. Through running applicationsoftware installed in a smartphone, for example, it is possible toexecute a function such as a digital still camera and car navigation. Inthese years, with advancement in augmented reality (AR) technology, ithas been achievable to add various information to images taken throughan imaging lens. For a purpose of achieving those various functions,many models of smartphones have a built-in camera.

In order to take a high-definition image of an object, an imagingelement with a higher pixel count and an imaging lens with highresolution are required. As one of methods to achieve higher resolutionof an imaging lens, the number of lenses that compose an imaging lensmay be increased. In case of this method, however, the size of theimaging lens may be easily increased if the number of lenses is simplyincreased. In developing an imaging lens, it is necessary to improve theresolution, while restraining extension of a total track length (TTL).

In case of a lens configuration comprised of nine lenses, since thenumber of lenses that compose the imaging lens is large, it has higherflexibility in designing and can satisfactorily correct aberrations thatare required for an imaging lens with high resolution. For example, asthe conventional imaging lens having a nine-lens configuration, animaging lens described in Patent Reference has been known.

PATENT REFERENCE

Patent Reference: Japanese Patent Application Publication No.2018-156011

Patent Reference describes an imaging lens including a first lens grouphaving positive refractive power and a second lens group having positiverefractive power. The first lens group includes six lenses, i.e., afirst lens that is positive; a second lens that is positive; a thirdlens that is negative; a fourth lens that is negative; a fifth lens thatis positive; and a sixth lens that is positive. The second lens groupincludes three lenses, i.e., a seventh lens that is negative; an eighthlens that is negative; and a ninth lens that is positive. In the secondlens group, the seventh lens L7 is formed in a shape such that a surfacethereof on the image plane side has a concave shape, and the eighth lensis formed to have a shape of a meniscus lens directing a concave surfacethereof to the object side. According to the conventional imaging lensdescribed in Patent Reference, aberrations are satisfactorily correctedby restraining a ratio of a focal length of the seventh lens to a focallength of the eighth lens within a certain range.

According to the conventional imaging lens of Patent Reference, it isachievable to relatively satisfactorily correct aberrations. In case ofthe conventional imaging lens, however, a total track length is longrelative to a focal length of the whole lens system, so that it is notsuitable to mount in a smartphone, etc. According to the conventionalimaging lens of Patent Reference, it is difficult to correct aberrationsmore satisfactorily, while downsizing the imaging lens.

Here, such a problem is not specific to an imaging lens to be mounted insmartphones and cellular phones. Rather, it is a common problem for animaging lens to be mounted in a relatively small camera such as digitalstill cameras, portable information terminals, security cameras, onboardcameras and network cameras.

In view of the above-described problems in the conventional techniques,an object of the present invention is to provide an imaging lens thatcan attain both a small size and satisfactorily corrected aberrations ina balanced manner.

Further objects and advantages of the present invention will be apparentfrom the following description of the invention.

SUMMARY OF THE INVENTION

In order to attain the objects described above, an imaging lens of theinvention is configured to form an image of an object on an imagingelement. According to a first aspect of the invention, an imaging lensof the invention includes a first lens having positive refractive power,a second lens having negative refractive power, a third lens havingpositive refractive power, a fourth lens, a fifth lens, a sixth lens, aseventh lens, an eighth lens, and a ninth lens having negativerefractive power, arranged in the order from an object side to anseventh lens. A surface of the ninth lens on the image plane side isformed in an aspheric shape having an inflection point.

According to the imaging lens of the invention, the arrangement ofrefractive power of the three lenses disposed on the object side is inthe order of “positive-negative-positive”, so that it is suitablyachieved to downsize the imaging lens. In addition, the image plane-sidesurface of the ninth lens, which is the closest surface to the imageplane side, is formed in an aspheric shape having an inflexion point.Therefore, it is achievable to satisfactorily correct paraxialaberrations and aberrations at the periphery thereof, while suitablyrestraining an incident angle of a light beam emitted from the imaginglens to the image plane of an imaging element within the range of chiefray angle (CRA).

Here, in the invention, “lens” refers to an optical element havingrefractive power. Accordingly, the “lens” of the invention does notinclude an optical element such as a prism and a flat plate filter tochange a traveling direction of a light beam. Those optical elements maybe disposed before or after the imaging lens or between lenses asnecessary.

The imaging lens having the above-described configuration preferablysatisfy the following conditional expression (1):0.5<f123/f<2.5  (1)

According to the imaging lens of the invention, nine lenses are disposedin the order from the object side. Among them, when a compositerefractive power of the three lenses close to the object side isrestrained within the range of the conditional expression (1), it isachievable to satisfactorily correct aberrations including a sphericalaberration.

The imaging lens having the above-described configuration preferablysatisfy the following conditional expression (2):f789<0  (2)

When the imaging lens satisfies the conditional expression (2), it ismore suitably achievable to downsize the imaging lens.

The imaging lens having the above-described configuration preferablysatisfy the following conditional expression (3):−6<f3/f2<−0.2  (3)

When the imaging lens satisfies the conditional expression (3), it isachievable to satisfactorily correct a chromatic aberration, astigmatismand a distortion in a well-balanced manner, while securing the backfocal length.

The imaging lens having the above-described configuration preferablysatisfy the following conditional expression (4):0.003<D34/f<0.04  (4)

When the imaging lens satisfies the conditional expression (4), it isachievable to satisfactorily correct the astigmatism and the distortion,while securing a distance between the third lens and the fourth lens andthe back focal length.

According to a second aspect of the invention, when the thickness of theseventh lens on the optical axis is T7 and the thickness of the eighthlens on the optical axis is T8, the imaging lens having theabove-described configuration preferably satisfies the followingconditional expression (5):0.5<T8/T7<4  (5)

When the total track length of the imaging lens is shortened relative toan image height of the imaging element, an effective diameter tends tobe larger as the lens is close to the image plane. When the imaging lenssatisfies the conditional expression (5), it is achievable tosatisfactorily keep the thicknesses of the seventh lens and the eighthlens, effective diameters of which tend to be large. Therefore, it isachievable to satisfactorily correct aberrations, while downsizing theimaging lens. In addition, it is also achievable to secure the backfocal length.

According to a third aspect of the invention, when the whole lens systemhas the focal length f and a distance on the optical axis between theeighth lens and the ninth lens is D89, the imaging lens having theabove-described configuration preferably satisfies the followingconditional expression (6):0.05<D89/f<0.15  (6)

When the imaging lens satisfies the conditional expression (6), it isachievable to satisfactorily correct a field curvature, the astigmatismand the distortion, while securing the back focal length.

According to a fourth aspect of the invention, when the whole lenssystem has the focal length f and a paraxial curvature radius of animage plane-side surface of the ninth lens is R9r, the imaging lenshaving the above-described configuration preferably satisfies thefollowing conditional expression (7):0.2<R9r/f<0.6  (7)

The image plane-side surface of the ninth lens is a surface positionedclosest to the image plane side in the imaging lens. Difficulty ofcorrecting the astigmatism, the coma aberration and the distortionvaries depending on the magnitude of the refractive power of the imageplane-side surface of the ninth lens. When the imaging lens satisfiesthe conditional expression (7), it is achievable to satisfactorilycorrect the astigmatism, the coma aberration and the distortion, whiledownsizing the imaging lens. When the imaging lens satisfies theconditional expression (7), it is achievable to effectively secure theback focal length.

According to a fifth aspect of the invention, when the whole lens systemhas the focal length f and the ninth lens has a focal length f9, theimaging lens having the above-described configuration preferablysatisfies the following conditional expression (8):−2<f9/f<−0.2  (8)

When the imaging lens satisfies the conditional expression (8), it isachievable to secure the back focal length and satisfactorily correctthe field curvature, while restraining the incident angle of a lightbeam emitted from the imaging lens to the image plane within the rangeof CRA.

When the whole lens system has the focal length f and the fourth lenshas a focal length f4, the imaging lens having the above-describedconfiguration preferably satisfies the following conditional expression(9):10<|f4/f|<60  (9)

When the value satisfies the conditional expression (9), it isachievable to satisfactorily restrain the chromatic aberration, theastigmatism, the field curvature and the distortion within satisfactoryranges.

When the first lens has Abbe's number νd1, the second lens has Abbe'snumber νd2, and the third lens has Abbe's number νd3, the imaging lenshaving the above-described configuration preferably satisfies thefollowing conditional expressions (10) through (12):35<νd1<80  (10)10<νd2<30  (11)35<νd3<80  (12)

When the imaging lens satisfies the conditional expressions (10) through(12), it is achievable to satisfactorily correct the chromaticaberration.

When the whole lens system has the focal length f and a distance on theoptical axis from an object-side surface of the first lens to the imageplane is TL, the imaging lens having the above-described configurationpreferably satisfies the following conditional expression (13): When theimaging lens satisfies the conditional expression (13), it is achievableto suitably downsize the imaging lens.1.0<TL/f<1.5  (13)

Here, between the imaging lens and the image plane, typically, there isdisposed an insert such as an infrared cut-off filter and cover glass.In this specification, for the distance on the optical axis of thoseinserts, a distance in the air is employed.

Moreover, in these years, there is a strong demand for being able totake a wider range of an image through an imaging lens. An imaging lenshas been increasingly required to attain both a smaller size and widerangle of view in a balanced manner than before. Especially, in case ofan imaging lens to be mounted in a thin portable device, e.g.,smartphone, it is necessary to hold the imaging lens within a limitedspace. Therefore, there is a strict limitation in the total length ofthe imaging lens in the optical axis relative to a size of the imagingelement. When the distance on the optical axis from the object-sidesurface of the first lens to the image plane is TL and the maximum imageheight is Hmax, the imaging lens of the present invention preferablysatisfies the following conditional expression (14):1.0<TL/Hmax<1.8  (14)

When the sixth lens has positive refractive power and the seventh lenshas positive refractive power, and the whole lens system has the focallength f and the sixth lens has a focal length f6, the imaging lenshaving the above-described configuration preferably satisfies thefollowing conditional expression (15):1.5<f6/f<6  (15)

When the sixth lens has weak refractive power relative to the refractivepower of the whole lens system, it is achievable to have the sixth lensfunction as a correction lens primarily intended to correct theaberrations. When the imaging lens satisfies the conditional expressions(15), it is achievable to satisfactorily correct the coma aberration andthe astigmatism.

When the seventh lens has negative refractive power and the eighth lenshas positive refractive power, and the whole lens system has the focallength f and the eighth lens has a focal length f8, the imaging lenshaving the above-described configuration preferably satisfies thefollowing conditional expression (16):1<f8/f<6  (16)

When the imaging lens satisfies the conditional expression (16), it isachievable to satisfactorily correct the spherical aberration and thedistortion, while downsizing the imaging lens.

According to the invention, the respective lenses from the first lens tothe ninth lens are preferably arranged with certain air intervals. Whenthe respective lenses are arranged at certain air intervals, the imaginglens of the invention can have a lens configuration that does notcontain any cemented lens. In such lens configuration like this, sinceit is achievable to form all of the nine lenses that compose the imaginglens from plastic materials, it is achievable to suitably restrain themanufacturing cost of the imaging lens.

According to the imaging lens of the invention, it is preferred to formboth surfaces each of the first through the ninth lenses in asphericshapes. Forming the both surfaces of each lens in aspheric surfaces, itis achievable to more satisfactorily correct aberrations from proximityof the optical axis of the lens to the periphery thereof. Especially, itis achievable to satisfactorily correct aberrations at periphery of thelens(es).

According to the imaging lens having the above-described configuration,the first lens is preferably formed in a shape directing a convexsurface thereof to the object side. When the first lens is formed insuch a shape, it is achievable to suitably downsize the imaging lens.

According to the imaging lens having the above-described configuration,in the eighth lens and the ninth lens, at least two surfaces thereof arepreferably formed in an aspheric shape having an inflection point. Inaddition to the image plane-side surface of the ninth lens, when onemore surface is formed in an aspheric shape having an inflection point,it is achievable to more satisfactorily correct aberrations at peripheryof an image, while suitably restraining an incident angle of a lightbeam emitted from the imaging lens to the image plane within the rangeof CRA.

According to the invention, when the imaging lens has an angle of view2ω, the imaging lens preferably satisfies 65°≤2ω. When the imaging lenssatisfies this conditional expression, it is possible to attain a wideangle of the imaging lens, and thereby to suitably attain bothdownsizing and wider angle of the imaging lens in a balanced manner.

In case of an imaging element with a high pixel count, a light-receivingarea of each pixel decreases, so that an image tends to be dark. As amethod of correcting such darkness of the image, there is a method ofimproving light-receiving sensitivity of the imaging element by using anelectrical circuit. However, when the light-receiving sensitivityincreases, a noise component, which does not directly contribute toformation of an image, is also amplified. Accordingly, in order toobtain fully bright image without such electrical circuit, when thewhole lens system has the focal length f and the imaging lens has adiameter of entrance pupil Dep, the imaging lens having theabove-described configuration preferably satisfies the followingconditional expression (17):f/Dep<2.4  (17)

Here, according to the present invention, as described above, the shapesof the lenses are specified using positive/negative signs of thecurvature radii thereof. Whether the curvature radius of the lens ispositive or negative is determined based on general definition. Morespecifically, taking a traveling direction of light as positive, if acenter of a curvature radius is on the image plane side when viewed froma lens surface, the curvature radius is positive. If a center of acurvature radius is on the object side, the curvature radius isnegative. Therefore, “an object-side surface having a positive curvatureradius” means the object-side surface has a convex shape. “Anobject-side surface having a negative curvature radius” means the objectside surface has a concave shape. In addition, “an image plane-sidesurface having a positive curvature radius” means the image plane-sidesurface has a concave shape. “An image plane-side surface having anegative curvature radius” means the image plane-side surface has aconvex shape. Here, a curvature radius used herein refers to a paraxialcurvature radius, and may not fit to general shapes of the lenses intheir sectional views all the time.

According to the imaging lens of the invention, it is achievable toprovide an imaging lens having a small size, which is especiallysuitable for mounting in a small-sized camera, while having highresolution with satisfactory correction of aberrations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sectional view of a schematic configuration of an imaginglens in Numerical Data Example 1 of the present invention;

FIG. 2 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 1 ;

FIG. 3 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 1 ;

FIG. 4 shows a sectional view of a schematic configuration of an imaginglens in Numerical Data Example 2 of the present invention;

FIG. 5 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 4 ;

FIG. 6 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 4 ;

FIG. 7 shows a sectional view of a schematic configuration of an imaginglens in Numerical Data Example 3 of the present invention;

FIG. 8 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 7 ;

FIG. 9 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 7 ;

FIG. 10 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 4 of the present invention;

FIG. 11 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 10 ;

FIG. 12 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 10 ;

FIG. 13 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 5 of the present invention;

FIG. 14 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 13 ;

FIG. 15 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 13 ;

FIG. 16 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 6 of the present invention;

FIG. 17 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 16 ;

FIG. 18 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 16 ;

FIG. 19 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 7 of the present invention;

FIG. 20 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 19 ;

FIG. 21 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 19 ;

FIG. 22 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 8 of the present invention;

FIG. 23 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 22 ;

FIG. 24 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 22 ;

FIG. 25 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 9 of the present invention;

FIG. 26 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 25 ;

FIG. 27 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 25 ;

FIG. 28 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 10 of the present invention;

FIG. 29 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 28 ;

FIG. 30 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 28 ;

FIG. 31 shows a sectional view of a schematic configuration of animaging lens in Numerical Data Example 11 of the present invention;

FIG. 32 is an aberration diagram showing a lateral aberration of theimaging lens of FIG. 31 ;

FIG. 33 is an aberration diagram showing a spherical aberration,astigmatism, and a distortion of the imaging lens of FIG. 31 .

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereunder, referring to the accompanying drawings, embodiments of thepresent invention will be fully described.

FIGS. 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, and 31 , are schematicsectional views of the imaging lenses in Numerical Data Examples 1 to 11according to the embodiments, respectively. Since the imaging lenses inthose Numerical Data Examples have the same basic configuration, thelens configuration of the embodiment will be described with reference tothe sectional view of Numerical Data Example 1.

As shown in FIG. 1 , the imaging lens of the embodiment includes a firstlens L1 having positive refractive power; a second lens L2 havingnegative refractive power; a third lens L3 having positive refractivepower; a fourth lens L4; a fifth lens L5; a sixth lens L6; a seventhlens L7; an eighth lens L8; and a ninth lens having negative refractivepower, arranged in the order from an object side to an image plane side.In addition, between the ninth lens L9 and an image plane IM of animaging element, there is provided a filter 10. Here, the filter 10 isomissible.

The first lens L1 is formed in a shape such that a curvature radius r1of a surface thereof on the object-side and a curvature radius r2 of asurface thereof on the image plane side are both positive. The firstlens L1 has a shape of a meniscus lens directing a convex surfacethereof to the object side near the optical axis. The shape of the firstlens L1 may not be limited to the one in Numerical Data Example 1. Thefirst lens L1 can be formed in any shape as long as the refractive powerthereof is positive. In addition to the shape in Numerical Data Example1, the first lens L1 can be formed in a shape such that the curvatureradius r1 and the curvature radius r2 are both negative, or such thatthe curvature radius r1 is positive and the curvature radius r2 isnegative. The first of the above-described shapes is a shape directing aconcave surface thereof to the object side near the optical axis, andthe latter one is a shape of a biconvex lens near the optical axis. Inview of downsizing the imaging lens, the first lens L1 may be preferablyformed in a shape such that the curvature radius r1 is positive.

According to Numerical Data Example 1, there is provided an aperturestop ST on the object-side surface of the first lens L1. Here, theposition of the aperture stop ST may not be limited to the one inNumerical Data Example 1. The aperture stop ST can be provided closer tothe object-side than the first lens L1. Alternatively, the aperture stopST can be provided between the first lens L1 and the second lens L2;between the second lens L2 and the third lens L3; between the third lensL3 and the fourth lens L4; or the like.

The second lens L2 is formed in a shape such that a curvature radius r3of a surface thereof on the object-side and a curvature radius r4 of asurface thereof on the image plane side are both positive. The secondlens L2 has a shape of a meniscus lens directing a convex surfacethereof to the object side near the optical axis. The shape of thesecond lens L2 may not be limited to the one in Numerical DataExample 1. The second lens L2 can be formed in any shape as long as therefractive power thereof is negative. In addition to the shape inNumerical Data Example 1, the second lens L2 can be formed in a shapesuch that the curvature radius r3 and the curvature radius r4 are bothnegative, or such that the curvature radius r3 is negative and thecurvature radius r4 is positive. The first of the above-described shapesis a shape directing a concave surface thereof to the object side nearthe optical axis, and the latter one is a shape of a biconcave lens nearthe optical axis. In view of downsizing the imaging lens, the first lensL1 may be preferably formed in a shape such that the curvature radius r3is positive.

The third lens L3 is formed in a shape such that a curvature radius r5of a surface thereof on the object-side is positive and a curvatureradius r6 of a surface thereof on the image plane side is negative. Thethird lens L3 has a shape of a biconcave lens near the optical axis. Theshape of the third lens L3 may not be limited to the one in NumericalData Example 1. Numerical Data Examples 3, 7, and 11 are examples of ashape, in which the curvature radii r5 and r6 are both positive, i.e., ashape of a meniscus lens directing a convex surface thereof to theobject side near the optical axis. Numerical Data Examples 5, and 10 areexamples of a shape, in which the curvature radii r5 and r6 are bothnegative, i.e., a shape of a meniscus lens directing a concave surfacethereof to the object side near the optical axis. The third lens L3 canbe formed in any shape as long as the refractive power thereof ispositive.

The fourth lens L4 has positive refractive power.

The fourth lens L4 is formed in a shape such that a curvature radius r7of a surface thereof on the object-side and a curvature radius r8 of asurface thereof on the image plane side are both negative. The fourthlens L4 has a shape of a meniscus lens directing a concave surfacethereof to the object side near the optical axis. The shape of thefourth lens L4 may not be limited to the one in Numerical DataExample 1. Numerical Data Examples 2, and 4 are examples of a shape, inwhich the curvature radii r7 and r8 are both positive, i.e., a shape ofa meniscus lens directing a convex surface thereof to the object sidenear the optical axis. The Numerical Data Examples 3, 7, 10, and 11 areexamples of a shape, in which the curvature radius r7 is positive andthe curvature radius r8 is negative, so as to have a shape of a biconvexlens near the optical axis.

According to the embodiment, the imaging lens satisfies the followingconditional expression:0<f34.

In the above formula, f34 is a composite focal length of the third lensL3 and the fourth lens L4.

The fifth lens L5 has positive refractive power. The refractive power ofthe fifth lens L5 is not limited to positive refractive power. NumericalData Examples 5 through 11 are examples of lens configurations, in whichthe fifth lens L5 has negative refractive power.

The fifth lens L5 is formed in a shape such that a curvature radius r9of a surface thereof on the object-side is positive and a curvatureradius r10 of a surface thereof on the image plane side is negative. Thefifth lens L5 has a shape of a biconvex lens near the optical axis. Theshape of the fifth lens L5 may not be limited to the one in NumericalData Example 1. Numerical Data Examples 3, 6 through 11 are examples ofa shape, in which the curvature radii r9 and r10 are both negative,i.e., a shape of a meniscus lens directing a concave surface thereof tothe object side near the optical axis. The Numerical Data Examples 5 isan example of a shape, in which the curvature radius r9 is negative andthe curvature radius r10 is positive, so as to have a shape of abiconcave lens near the optical axis.

The sixth lens L6 has negative refractive power. The refractive power ofthe sixth lens L6 is not limited to negative refractive power. NumericalData Examples 5 through 8 are examples of lens configurations, in whichthe sixth lens L6 has positive refractive power.

The sixth lens L6 is formed in a shape such that a curvature radius r11of a surface thereof on the object-side and a curvature radius r12 of asurface thereof on the image plane side are both positive. The sixthlens L6 has a shape of a meniscus lens directing a convex surfacethereof to the object side near the optical axis. The shape of the sixthlens L6 may not be limited to the one in Numerical Data Example 1.Numerical Data Examples 2 through 4, and 6 through 11 are examples of ashape, in which the curvature radii r11 and r12 are both negative, i.e.,a shape of a meniscus lens directing a concave surface thereof to theobject side near the optical axis. The Numerical Data Examples 5 is anexample of a shape, in which the curvature radius r11 is positive andthe curvature radius r12 is negative, so as to have a shape of abiconvex lens near the optical axis.

The seventh lens L7 has positive refractive power. The refractive powerof the seventh lens L7 is not limited to positive refractive power.Numerical Data Examples 3, 4, 7, 8 and 11 are examples of lensconfigurations, in which the seventh lens L7 has negative refractivepower.

The seventh lens L7 is formed in a shape, such that a curvature radiusr13 of a surface thereof on the object-side and a curvature radius r14of a surface thereof on the image plane side are both negative. Theseventh lens L7 has a shape of a meniscus lens directing a concavesurface thereof to the object side near the optical axis. The shape ofthe seventh lens L7 may not be limited to the one in Numerical DataExample 1. In addition to the shapes described above, the seventh lensL7 can be formed in a shape such that the curvature radius r13 ispositive and the curvature radius r14 is negative, or such that thecurvature radius r13 is negative and the curvature radius r14 ispositive.

The eighth lens L8 has positive refractive power. The refractive powerof the eighth lens L8 is not limited to positive refractive power.Numerical Data Examples 2, 4, 6, 8 and 10 are examples of lensconfigurations, in which the eighth lens L8 has negative refractivepower.

The eighth lens L8 is formed in a shape such that a curvature radius r15of a surface thereof on the object-side and a curvature radius r16 of asurface thereof on the image plane side are both positive. The eighthlens L8 has a shape of a meniscus lens directing a convex surfacethereof to the object side near the optical axis. The shape of theeighth lens L8 may not be limited to the one in Numerical DataExample 1. Numerical Data Examples 6 and 8 are examples of a shape, inwhich the curvature radii r15 and r16 are both negative, i.e., a shapeof a meniscus lens directing a concave surface thereof to the objectside near the optical axis. In addition to the shapes described above,the eighth lens L8 can be formed in a shape such that the curvatureradius r15 is negative and the curvature radius r16 is positive.

The ninth lens L9 is formed in a shape such that a curvature radius r17of a surface thereof on the object-side and a curvature radius r18(=R9r) of a surface thereof on the image plane side are both positive.The ninth lens L9 has a shape of a meniscus lens directing a convexsurface thereof to the object side near the optical axis. The shape ofthe ninth lens L9 may not be limited to the one in Numerical DataExample 1. The Numerical Data Examples 5 and 10 are examples of a shape,in which the curvature radius r17 is negative and the curvature radiusr18 is positive, so as to have a shape of a biconcave lens near theoptical axis. In addition to the shapes described above, the ninth lensL9 can be formed in a shape such that the curvature radius r17 and thecurvature radius r18 are both negative. The ninth lens L9 can be formedin any shape as long as the refractive power thereof is negative.

The ninth lens L9 is formed in a shape such that a surface thereof onthe image plane side has an aspheric shape having an inflection point.Here, the “inflection point” means a point where the positive/negativesign of a curvature radius changes on the curve, i.e., a point where adirection of curving of the curve on the lens surface changes. Accordingto the imaging lens of the embodiment, the image plane-side surface ofthe ninth lens L9 is formed as an aspheric shape having an extremepoint. With such shape of the ninth lens L9, it is achievable tosatisfactorily correct off-axis chromatic aberration of magnification aswell as axial chromatic aberration, and to suitably restrain theincident angle of a light beam emitted from the imaging lens to theimage plane within the range of the chief ray angle (CRA). According tothe imaging lens of Numerical Data Example 1, both surfaces of theeighth lens L8 and the ninth lens L9 are formed as aspheric shapeshaving an inflection point. For this reason, it is achievable to moresatisfactorily correct aberrations at periphery of the image, whilerestraining the incident angle of a light beam emitted from the imaginglens within the range of CRA. Here, depending on the required opticalperformance and downsizing of the imaging lens, among lens surfaces ofthe eighth lens L8 and the ninth lens L9, lens surfaces other than theimage plane-side surface of the ninth lens L9 can be formed as anaspheric shape without an inflection point.

According to the embodiment, the imaging lens satisfied the followingconditional expressions (1) through (14):0.5<f123/f<2.5  (1)f789<0  (2)−6<f3/f2<−0.2  (3)0.003<D34/f<0.04  (4)0.5<T8/T7<4  (5)0.05<D89/f<0.15  (6)0.2<R9r/f<0.6  (7)−2<f9/f<−0.2  (8)10<|f4/f|<60  (9)35<νd1<80  (10)10<νd2<30  (11)35<νd3<80  (12)1.0<TL/f<1.5  (13)1.0<TL/Hmax<1.8  (14)

In the above conditional expressions,

f: Focal length of the whole lens system

f2: Focal length of the second lens L2

f3: Focal length of the third lens L3

f4: Focal length of the fourth lens L4

f9: Focal length of the ninth lens L9

f123: Composite focal length of the first lens L1, the second lens L2and the third lens L3

f789: Composite focal length of the seventh lens L7, the eighth lens L8and the ninth lens L9

T7: Thickness of the seventh lens L7 on an optical axis

T8: Thickness of the eighth lens L8 on an optical axis

νd1: Abbe's number of the first lens L1

νd2: Abbe's number of the second lens L2

νd3: Abbe's number of the third lens L3

R9r: Paraxial curvature radius of an image plane-side surface of theninth lens L9

D34: Distance on the optical axis X between the third lens L3 and thefourth lens L4

D89: Distance on the optical axis X between the eighth lens L8 and theninth lens L9

Hmax: Maximum image height

TL: Distance on an optical axis X from the object-side surface of thefirst lens L1 to the image plane IM (the filter 10 is a distance in theair)

When the sixth lens L6 has positive refractive power and the seventhlens L7 has positive refractive power as in the lens configurations inNumerical Data Examples 5 and 6, the imaging lens further satisfies thefollowing conditional expression (15):1.5<f6/f<6  (15)

In the above conditional expressions, f6 is a focal length of the sixthlens L6.

When the seventh lens L7 has negative refractive power and the eighthlens L8 has positive refractive power as in the lens configurations inNumerical Data Examples 3, 7 and 11, the imaging lens further satisfiesthe following conditional expression (16):1<f8/f<6  (16)

In the above conditional expression, f8 is a focal length of the eighthlens L8.

According to the embodiment, the imaging lens satisfies the followingconditional expression (17):f/Dep<2.4  (17)

In the above conditional expression, Dep is a diameter of entrance pupilof the imaging lens.

Here, it is not necessary to satisfy all of the conditional expressions,and it is achievable to obtain an effect corresponding to the respectiveconditional expression when any single one of the conditionalexpressions is individually satisfied.

According to the embodiment, lens surfaces of the respective lenses areformed as aspheric surfaces. An equation that expresses those asphericsurfaces is shown below:

$\begin{matrix}{Z = {\frac{C \cdot H^{2}}{1 + \sqrt{1 - {\left( {1 + k} \right) \cdot C^{2} \cdot H^{2}}}} + {\sum\left( {A{n \cdot H^{n}}} \right)}}} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In the above conditional expression,

Z: Distance in a direction of the optical axis

H: Distance from the optical axis in a direction perpendicular

to the optical axis

C: Paraxial curvature (=1/r, r: paraxial curvature radius)

k: Conic constant

An: The nth aspheric coefficient

Next, Numerical Data Examples of the imaging lens of the embodiment willbe described. In each Numerical Data Example, f represents a focallength of the whole lens system, Fno represents a F-number, and ωrepresents a half angle of view, respectively. In addition, i representsa surface number counted from the object side, r represents a curvatureradius, d represents a distance on the optical axis between lenssurfaces (surface spacing), nd represents a refractive index at areference wavelength of 588 nm, and νd represents an Abbe's number atthe reference wavelength, respectively. Here, surfaces indicated withsurface numbers i affixed with * (asterisk) are aspheric surfaces.

Numerical Data Example 1

Basic Lens Data

TABLE 1 f = 5.68 mm Fno = 1.9 ω = 39.6° i r d n d ν d [mm] ∞ ∞ L1  1*2.449 0.735 1.5443 55.9 f1 = 4.927    2*(ST) 25.250 0.053 L2  3* 3.8730.232 1.6707 19.2 f2 = −11.959  4* 2.549 0.451 L3  5* 29.386 0.3221.5443 55.9 f3 = 39.344  6* −78.645 0.164 L4  7* −15.450 0.368 1.544355.9 f4 = 254.929  8* −14.019 0.031 L5  9* 73.756 0.335 1.5443 55.9 f5 =31.319 10* −22.136 0.084 L6 11* 10.710 0.320 1.5443 55.9 f6 = −76.82212* 8.436 0.337 L7 13* −3.849 0.307 1.6707 19.2 f7 = 73.662 14* −3.6850.103 L8 15* 5.770 0.593 1.5443 55.9 f8 = 12.656 16* 34.237 0.505 L9 17*12.431 0.627 1.5443 55.9 f9 = −5.133 18* 2.241 0.280 19  ∞ 0.210 1.516864.2 20  ∞ 0.774 (IM) ∞f123=6.413 mmf789=−12.710 mmf34=34.396 mmf89=−10.730 mmT7=0.307 mmT8=0.593 mmD34=0.164 mmD89=0.505 mmTL=6.759 mmHmax=4.70 mmDep=3.004 mm

TABLE 2 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 1 1.596E−01−2.809E−05 −1.763E−03  1.538E−03 −1.234E−03   3.575E−04 2.314E−05−2.293E−05 2 0.000E+00 −2.103E−02  2.809E−02 −1.854E−02 6.964E−03−1.155E−03 −4.096E−05   1.997E−05 3 −1.592E+01  −3.180E−02  3.591E−02−2.036E−02 7.277E−03 −7.931E−04 −2.521E−04   3.892E−05 4 −1.055E+01  2.966E−02 −2.000E−02  1.781E−02 −7.661E−03   2.505E−03 −7.223E−04  2.167E−04 5 −3.340E+03  −5.173E−03 −5.960E−03 −4.977E−04 −9.541E−04  5.056E−04 3.619E−04  1.287E−05 6 0.000E+00 −2.367E−02 −4.644E−03−2.003E−03 −1.931E−04   3.362E−04 1.312E−04  5.003E−05 7 0.000E+00−1.139E−02 −1.414E−02  2.120E−03 2.433E−04 −4.450E−05 6.296E−05 1.362E−05 8 0.000E+00 −9.928E−03 −1.849E−02 −3.913E−05 1.469E−03 2.732E−05 −2.115E−04  −5.735E−07 9 0.000E+00 −2.701E−02 −1.053E−02 6.084E−05 −5.033E−04   5.285E−05 1.589E−04 −5.141E−05 10 0.000E+00−1.728E−02 −1.322E−02 −3.890E−04 1.106E−03  6.911E−05 −1.770E−04  5.570E−05 11 0.000E+00 −6.285E−03 −1.675E−02  1.414E−03 −6.246E−04 −1.600E−05 1.467E−04 −3.402E−05 12 0.000E+00 −2.921E−02  1.024E−02−5.023E−03 −1.718E−03   1.892E−03 −4.964E−04   4.178E−05 13 1.722E+00−1.581E−03  2.259E−02 −1.508E−02 5.786E−03 −1.060E−03 6.904E−05−4.463E−07 14 −5.681E+00  −1.732E−02  2.294E−02 −1.170E−02 3.418E−03−5.125E−04 3.017E−05 −2.400E−07 15 −1.545E+00  −8.400E−03  1.712E−03−2.780E−03 5.804E−04 −9.580E−05 1.110E−05 −4.282E−07 16 0.000E+00 1.692E−02 −4.024E−03 −6.828E−04 1.790E−04 −1.078E−05 1.733E−07−2.112E−09 17 6.588E+00 −8.207E−02  1.852E−02 −2.344E−03 2.140E−04−1.420E−05 5.771E−07 −1.023E−08 18 −5.072E+00  −5.346E−02  1.438E−02−2.864E−03 3.587E−04 −2.641E−05 1.028E−06 −1.607E−08

The values of the respective conditional expressions are as follows:f123/f=1.129f3/f2=−3.290D34/f=0.029T8/T7=1.932D89/f=0.089R9r/f=0.395f9/f=−0.904|f4/f|=44.882TL/f=1.190TL/Hmax=1.438f/Dep=1.89

Accordingly, the imaging lens of Numerical Data Example 1 satisfies theabove-described conditional expressions.

FIG. 2 shows a lateral aberration that corresponds to a half angle ofview co, which is divided into a tangential direction and a sagittaldirection (The same is true for FIGS. 5, 8, 11, 14, 17, 20, 23, 26, 29and 32 ). FIG. 3 shows a spherical aberration (mm), astigmatism (mm),and a distortion (%), respectively. The aberration diagrams of theastigmatism and the distortion show aberrations at a referencewavelength (588 nm). Furthermore, in the aberration diagrams of theastigmatism shows sagittal image planes (S) and tangential image planes(T), respectively (The same is true for FIGS. 6, 9, 12, 15, 18, 21, 24,27, 30 and 33 ). As shown in FIGS. 2 and 3 , according to the imaginglens of Numerical Data Example 1, the aberrations can be satisfactorilycorrected.

Numerical Data Example 2

Basic Lens Data

TABLE 3 f = 6.08 mm Fno = 2.2 ω = 37.7° i r d n d ν d [mm] ∞ ∞ L1  1*2.334 0.745 1.5443 55.9 f1 = 4.893    2*(ST) 16.738 0.021 L2  3* 5.0430.285 1.6707 19.2 f2 = −13.267  4* 3.146 0.524 L3  5* 80.262 0.5601.5443 55.9 f3 = 50.126  6* −41.233 0.067 L4  7* 27.557 0.369 1.544355.9 f4 = 86.620  8* 66.007 0.323 L5  9* 19.502 0.511 1.5443 55.9 f5 =13.343 10* −11.465 0.254 L6 11* −2.954 0.252 1.6707 19.2 f6 = −87383 12*−3.217 0.042 L7 13* −5.926 0.322 1.5443 55.9 f7 = 100.754 14* −5.4510.031 L8 15* 16.055 0.299 1.5443 55.9 f8 = −81.403 16* 11.707 0.540 L917* 83.889 0.790 1.5443 55.9 f9 = −5.485 18* 2.873 0.250 19  ∞ 0.2101.5168 64.2 20  ∞ 0.635 (IM) ∞f123=6.268 mmf789=−5.342 mmf34=31.756 mmf89=−5.107 mmT7=0.322 mmT8=0.299 mmD34=0.067 mmD89=0.540 mmTL=6.956 mmHmax=4.70 mmDep=2.763 mm

TABLE 4 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 1 4.880E−01−5.227E−03 −3.718E−03   4.169E−04 7.015E−05 −8.771E−04 4.755E−04−1.018E−04  2 0.000E+00 −4.515E−02 5.024E−02 −3.097E−02 8.543E−03 1.986E−04 −7.102E−04  1.067E−04 3 −2.868E+01  −2.082E−02 3.165E−02−1.242E−02 1.722E−03 −4.847E−04 7.671E−04 −2.241E−04  4 −5.582E+00  1.580E−02 −1.515E−02   4.259E−02 −4.677E−02   3.176E−02 −1.260E−02 2.516E−03 5 0.000E+00 −1.786E−02 −6.527E−03  −2.481E−03 7.567E−03−8.257E−03 3.355E−03 1.454E−05 6 0.000E+00 −5.176E−02 −2.188E−02 −5.025E−03 1.134E−02 −2.738E−04 −2.384E−03  7.130E−04 7 0.000E+00−3.577E−02 −2.207E−02   7.948E−03 1.122E−03  1.330E−03 7.454E−05−2.252E−04  8 0.000E+00 −3.611E−02 9.891E−03 −4.100E−03 6.217E−04 6.418E−04 −4.383E−04  1.514E−04 9 0.000E+00 −5.604E−02 5.027E−03−1.294E−02 6.302E−03 −2.229E−03 2.535E−04 2.055E−05 10 0.000E+00−2.273E−02 3.461E−03 −1.281E−03 −2.300E−03   1.270E−03 −1.944E−04 1.625E−06 11 −4.159E−02  −2.244E−02 1.538E−02 −1.151E−04 −7.550E−04  1.965E−04 −5.221E−05  2.364E−06 12 −5.116E+00  −4.191E−02 1.753E−02−5.069E−03 2.133E−03 −4.527E−04 6.806E−06 4.074E−06 13 0.000E+00 3.671E−03 3.116E−03 −3.195E−03 3.982E−04 −2.701E−05 1.442E−05−1.709E−06  14 0.000E+00  1.202E−02 −5.005E−03  −4.778E−05 1.706E−04−6.530E−06 −7.463E−07  −8.462E−08  15 0.000E+00 −7.208E−03 −5.817E−03  2.652E−04 3.604E−04 −1.080E−04 1.575E−05 −9.747E−07  16 0.000E+00−1.428E−02 1.413E−03 −6.500E−04 1.034E−04 −7.395E−06 6.189E−07−4.144E−08  17 0.000E+00 −8.241E−02 1.935E−02 −1.764E−03 3.096E−05 5.837E−06 −3.662E−07  4.905E−09 18 −7.681E+00  −4.147E−02 1.063E−02−1.960E−03 2.327E−04 −1.632E−05 6.130E−07 −9.504E−09 

The values of the respective conditional expressions are as follows:f123/f=1.031f3/f2=−3.778D34/f=0.011T8/T7=0.929D89/f=0.089R9r/f=0.473f9/f=−0.902|f4/f|=14.247TL/f=1.144TL/Hmax=1.480f/Dep=2.20

Accordingly, the imaging lens of Numerical Data Example 2 satisfies theabove-described conditional expressions.

FIG. 5 shows a lateral aberration that corresponds to an image height Hand FIG. 6 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 5 and 6 , according tothe imaging lens of Numerical Data Example 2, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 3

Basic Lens Data

TABLE 5 f = 6.10 mm Fno = 1.7 ω = 37.6° i r d n d ν d [mm] ∞ ∞ L1   1*(ST) 2.534 0.577 1.5443 55.9 f1 = 8.018  2* 5.559 0.033 L2  3*2.199 0.240 1.6707 19.2 f2 = −10.066  4* 1.586 0.128 L3  5* 2.805 0.7121.5348 55.7 f3 = 6.429  6* 13.883 0.112 L4  7* 75.096 0.251 1.5348 55.7f4 = 85.345  8* −116.235 0.245 L5  9* −41.080 0.268 1.5348 55.7 f5 =111.459 10* −24.375 0.272 L6 11* −4.590 0.321 1.6707 19.2 f6 = −94.51712* −5.087 0.159 L7 13* −6.282 0.549 1.6707 19.2 f7 = −31.919 14* −9.2040.027 L8 15* 4.172 0.518 1.5443 55.9 f8 = 26.274 16* 5.634 0.671 L9 17*3.773 0.556 1.5348 55.7 f9 = −8.687 18* 1.975 0.250 19  ∞ 0.210 1.516864.2 20  ∞ 0.923 (IM) ∞f123=5.726 mmf789=−9.353 mmf34=6.028 mmf89=−15.304 mmT7=0.549 mmT8=0.518 mmD34=0.112 mmD89=0.671 mmTL=6.950 mmHmax=4.70 mmDep=3.560 mm

TABLE 6 Aspherical surface data i k A4 A6 A8 A10 1 −6.443E−01  8.068E−03  2.143E−03 −1.571E−03   2.699E−04 2 0.000E+00  4.423E−02−6.432E−02 9.069E−02 −1.009E−01 3 −8.075E+00   5.014E−02 −7.690E−029.613E−02 −1.052E−01 4 −1.943E+00  −5.854E−02  7.888E−02 −1.103E−01  1.085E−01 5 −5.180E+00   3.599E−03  6.361E−02 −1.547E−01   2.239E−01 60.000E+00 −1.817E−02 −4.684E−03 4.819E−02 −9.273E−02 7 0.000E+00−1.870E−02  1.174E−02 2.065E−03 −3.820E−03 8 0.000E+00 −1.249E−02 6.136E−03 9.286E−04 −2.934E−03 9 0.000E+00 −3.254E−02 −1.131E−025.001E−03 −6.521E−03 10 0.000E+00 −4.119E−03 −2.761E−02 5.526E−03 2.886E−03 11 0.000E+00  4.230E−02 −7.700E−02 4.535E−02 −1.066E−02 120.000E+00  3.608E−02 −3.446E−02 −2.046E−02   3.227E−02 13 0.000E+00 1.616E−02  2.363E−02 −4.859E−02   2.608E−02 14 0.000E+00 −5.545E−03 5.230E−03 −1.835E−03  −4.943E−04 15 −8.101E−01  −1.282E−03 −3.680E−021.619E−02 −4.815E−03 16 0.000E+00  2.125E−02 −2.755E−02 7.708E−03−9.439E−04 17 −2.388E−01  −1.212E−01  3.978E−02 −8.483E−03   9.174E−0418 −7.024E+00  −5.145E−02  1.345E−02 −2.621E−03   3.137E−04 i A12 A14A16 A18 A20 1  5.319E−05 −8.179E−06 −5.405E−06 −4.391E−07 3.391E−07 2 7.464E−02 −3.519E−02  1.017E−02 −1.646E−03 1.145E−04 3  7.850E−02−3.720E−02  1.077E−02 −1.739E−03 1.201E−04 4 −7.483E−02  3.385E−02−9.262E−03  1.397E−03 −9.146E−05  5 −2.006E−01  1.105E−01 −3.620E−02 6.494E−03 −4.923E−04  6  9.979E−02 −6.273E−02  2.276E−02 −4.492E−033.863E−04 7  6.043E−04  7.213E−04 −9.371E−05 −2.118E−04 6.925E−05 8 3.337E−06  1.017E−03  2.281E−04 −2.943E−04 5.074E−05 9  6.027E−03−4.502E−04 −1.337E−03  7.273E−04 −1.460E−04  10 −1.187E−03 −3.307E−04 3.226E−04  1.941E−04 −1.145E−04  11 −1.862E−02  2.208E−02 −1.184E−02 3.740E−03 −5.594E−04  12 −2.077E−02  4.902E−03  1.598E−03 −1.058E−031.505E−04 13 −5.289E−03 −3.067E−03  2.823E−03 −8.450E−04 8.756E−05 14 2.061E−04  3.624E−05 −2.053E−05  1.805E−06 4.467E−08 15  1.194E−03−2.158E−04  1.281E−05  2.180E−06 −2.531E-07  16 −1.460E−05  1.486E−05−7.389E−07 −8.256E−08 6.679E−09 17 −2.334E−05 −2.352E−06 −1.087E−07 3.206E−08 −1.128E−09  18 −2.267E−05  9.665E−07 −1.989E−08 −2.224E−11−5.300E−13 

The values of the respective conditional expressions are as follows:f123/f=0.939f3/f2=−0.639D34/f=0.018T8/T7=0.944D89/f=0.110R9r/f=0.324f9/f=−1.424|f4/f|=13.991TL/f=1.139TL/Hmax=1.479f/Dep=1.71f8/f=4.307

Accordingly, the imaging lens of Numerical Data Example 3 satisfies theabove-described conditional expressions.

FIG. 8 shows a lateral aberration that corresponds to an image height Hand FIG. 9 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 8 and 9 , according tothe imaging lens of Numerical Data Example 3, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 4

Basic Lens Data

TABLE 7 f = 6.15 mm Fno = 2.2 ω = 37.4° i r d n d ν d [mm] ∞ ∞ L1  1*2.328 0.747 1.5443 55.9 f1 = 4.884    2*(ST) 16.630 0.021 L2  3* 5.0450.291 1.6707 19.2 f2 = −13.349  4* 3.152 0.527 L3  5* 78.026 0.5641.5443 55.9 f3 = 49.231  6* −40.709 0.068 L4  7* 26.693 0.370 1.544355.9 f4 = 82.983  8* 64.944 0.330 L5  9* 18.893 0.512 1.5443 55.9 f5 =12.970 10* −11.164 0.260 L6 11* −2.964 0.258 1.6707 19.2 f6 = −101.03812* −3.208 0.042 L7 13* −5.877 0.309 1.5443 55.9 f7 = −101.235 14*−6.700 0.031 L8 15* 15.450 0.297 1.5443 55.9 f8 = −105.279 16* 12.0870.548 L9 17* 68.554 0.800 1.5443 55.9 f9 = −5.686 18* 2.949 0.250 19  ∞0.210 1.5168 64.2 20  ∞ 0.609 (IM) ∞f123=6.222 mmf789=−4.958 mmf34=30.906 mmf89=−5.376 mmT7=0.309 mmT8=0.297 mmD34=0.068 mmD89=0.548 mmTL=6.971 mmHmax=4.70 mmDep=2.795 mm

TABLE 8 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 1 4.905E−01−5.253E−03 −3.630E−03   4.287E−04 5.915E−05 −8.812E−04 4.766E−04−9.963E−05  2 0.000E+00 −4.533E−02 5.034E−02 −3.097E−02 8.548E−03 2.118E−04 −7.034E−04  1.042E−04 3 −2.841E+01  −2.107E−02 3.156E−02−1.235E−02 1.760E−03 −4.894E−04 7.575E−04 −2.218E−04  4 −5.526E+00  1.590E−02 −1.504E−02   4.273E−02 −4.672E−02   3.175E−02 −1.261E−02 2.503E−03 5 0.000E+00 −1.782E−02 −6.261E−03  −2.392E−03 7.476E−03−8.379E−03 3.302E−03 4.602E−05 6 0.000E+00 −5.258E−02 −2.200E−02 −5.070E−03 1.130E−02 −2.974E−04 −2.390E−03  7.175E−04 7 0.000E+00−3.545E−02 −2.222E−02   7.892E−03 1.149E−03  1.383E−03 1.068E−04−2.386E−04  8 0.000E+00 −3.541E−02 1.040E−02 −3.968E−03 6.473E−04 6.503E−04 −4.314E−04  1.537E−04 9 0.000E+00 −5.646E−02 5.381E−03−1.285E−02 6.342E−03 −2.197E−03 2.621E−04 1.114E−05 10 0.000E+00−2.251E−02 3.392E−03 −1.290E−03 −2.286E−03   1.271E−03 −1.958E−04 1.420E−06 11 3.865E−02 −2.312E−02 1.522E−02 −1.157E−04 −7.537E−04  1.988E−04 −5.157E−05  2.139E−06 12 −4.861E+00  −4.235E−02 1.738E−02−5.080E−03 2.137E−03 −4.522E−04 6.774E−06 4.109E−06 13 0.000E+00 3.675E−03 2.988E−03 −3.217E−03 3.889E−04 −2.773E−05 1.468E−05−1.593E−06  14 0.000E+00  1.141E−02 −5.033E−03  −5.806E−05 1.693E−04−6.763E−06 −7.718E−07  −8.299E−08  15 0.000E+00 −6.789E−03 −5.857E−03  2.697E−04 3.606E−04 −1.079E−04 1.576E−05 −9.752E−07  16 0.000E+00−1.465E−02 1.471E−03 −6.524E−04 1.032E−04 −7.362E−06 6.296E−07−3.978E−08  17 0.000E+00 −8.270E−02 1.936E−02 −1.763E−03 3.099E−05 5.837E−06 −3.664E−07  4.882E−09 18 −8.125E+00  −4.158E−02 1.061E−02−1.960E−03 2.328E−04 −1.632E−05 6.127E−07 −9.507E−09 

The values of the respective conditional expressions are as follows:f123/f=1.012f3/f2=−3.688D34/f=0.011T8/T7=0.961D89/f=0.089R9r/f=0.480f9/f=−0.925|f4/f|=13.493TL/f=1.133TL/Hmax=1.483f/Dep=2.20

Accordingly, the imaging lens of Numerical Data Example 4 satisfies theabove-described conditional expressions.

FIG. 11 shows a lateral aberration that corresponds to an image height Hand FIG. 12 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 11 and 12 , according tothe imaging lens of Numerical Data Example 4, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 5

Basic Lens Data

TABLE 9 f = 5.62 mm Fno = 2.0 ω = 39.9° i r d n d ν d [mm] ∞ ∞ L1   1*(ST) 2.528 0.665 1.5443 55.9 f1 = 5.246  2* 19.980 0.072 L2  3*53.71 0.323 1.6707 19.2 f2 = −13.117  4* 3.254 0.469 L3  5* −77.3320.246 1.5443 55.9 f3 = 67.060  6* −24.824 0.095 L4  7* −97.181 0.3211.5443 55.9 f4 = 98.720  8* −34.642 0.045 L5  9* −63.761 0.292 1.544355.9 f5 = −53.017 10* 52.800 0.306 L6 11* 13.401 0.554 1.5443 55.9 f6 =14.163 12* −17.886 0.354 L7 13* −3.237 0.316 1.6707 19.2 f7 = 29.675 14*−2.893 0.030 L8 15* 5.363 0.601 1.5443 55.9 f8 = 16.653 16* 12.613 0.570L9 17* −83.897 0.600 1.5443 55.9 f9 = −4.505 18* 2.532 0.250 19  ∞ 0.2101.5168 64.2 20  ∞ 0.695 (IM) ∞f123=7.083 mmf789=−9.850 mmf34=40.016 mmf89=−7.116 mmT7=0.316 mmT8=0.601 mmD34=0.095 mmD89=0.570 mmTL=6.941 mmHmax=4.70 mmDep=2.836 mm

TABLE 10 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 12.824E−01  8.742E−05 −2.220E−04  7.294E−04 −6.360E−04  2.431E−04−4.372E−06  −1.690E−05 2 0.000E+00 −1.786E−02  2.214E−02 −1.385E−024.869E−03 −7.111E−04  −4.637E−05   1.137E−05 3 −1.992E+01  −2.365E−02 2.415E−02 −1.356E−02 4.928E−03 −7.753E−04  1.287E−04 −3.491E−05 4−1.242E+01   2.203E−02 −1.379E−02  1.245E−02 −5.473E−03  1.695E−03−2.851E−04   2.011E−04 5 0.000E+00 −1.218E−02 −9.821E−03 −4.108E−04−3.369E−04  2.288E−04 2.228E−04  1.291E−05 6 0.000E+00 −6.273E−03−1.042E−02 −9.206E−04 3.279E−04 1.692E−04 6.659E−05 −2.902E−05 70.000E+00 −1.244E−02 −9.295E−03 −2.477E−04 −4.349E−04  9.790E−051.540E−04  1.116E−05 8 0.000E+00 −6.064E−03 −1.130E−02 −1.141E−033.635E−04 2.092E−04 6.357E−05 −5.938E−05 9 0.000E+00 −1.824E−02−3.106E−03  1.546E−03 1.031E−04 1.632E−04 1.474E−05 −4.076E−05 100.000E+00 −4.479E−02  4.468E−04  1.074E−03 4.161E−04 6.566E−05−2.909E−05   8.274E−06 11 0.000E+00 −3.644E−02  7.678E−05 −2.609E−03−5.616E−05  2.973E−04 5.830E−05 −1.870E−05 12 0.000E+00 −5.140E−02 1.069E−02 −2.252E−03 −1.306E−03  1.134E−03 −2.692E−04   2.192E−05 137.454E−01 −1.881E−02  2.193E−02 −1.220E−02 4.184E−03 −6.775E−04 2.736E−05  2.134E−06 14 −5.470E+00  −2.135E−02  1.639E−02 −8.535E−032.327E−03 −3.048E−04  1.725E−05 −4.044E−07 15 0.000E+00 −1.501E−02−8.166E−04 −1.211E−03 3.374E−04 −5.781E−05  5.423E−06 −1.809E−07 160.000E+00 −3.621E−03 −5.245E−04 −6.036E−04 1.163E−04 −7.958E−06 −2.238E−08   2.470E−08 17 0.000E+00 −6.988E−02  1.536E−02 −1.778E−031.444E−04 −8.506E−06  3.130E−07 −5.120E−09 18 −5.780E+00  −4.497E−02 1.162E−02 −2.096E−03 2.376E−04 −1.595E−05  5.772E−07 −8.663E−09

The values of the respective conditional expressions are as follows:f123/f=1.260f3/f2=−5.112D34/f=0.017T8/T7=1.902D89/f=0.101R9r/f=0.451f9/f=−0.802|f4/f|=17.566TL/f=1.235TL/Hmax=1.477f/Dep=1.98f6/f=2.520

Accordingly, the imaging lens of Numerical Data Example 5 satisfies theabove-described conditional expressions.

FIG. 14 shows a lateral aberration that corresponds to an image height Hand FIG. 15 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 14 and 15 , according tothe imaging lens of Numerical Data Example 5, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 6

Basic Lens Data

TABLE 11 f = 5.92 mm Fno = 2.2 ω = 38.4° i r d n d ν d [mm] ∞ ∞ L1  1*2.815 0.598 1.5443 55.9 f1 = 5.382    2*(ST) 67.083 0.058 L2  3* 4.0220.263 1.6707 19.2 f2 = −12.884  4* 2.673 0.471 L3  5* 14.261 0.5011.5443 55.9 f3 = 12.951  6* −13.767 0.122 L4  7* −22.961 0.362 1.544355.9 f4 = 148.629  8* −17.985 0.223 L5  9* −13.752 0.288 1.5443 55.9 f5= −106.392 10* −18.168 0.061 L6 11* −19.022 0.317 1.5443 55.9 f6 =18.645 12* −6.657 0.053 L7 13* −4.210 0.295 1.6707 19.2 f7 = 65.956 14*−3.953 0.218 L8 15* −15.182 1.000 1.5443 55.9 f8 = −95.383 16* −21.9540.564 L9 17* 97.563 0.749 1.5443 55.9 f9 = −4.705 18* 2.489 0.300 19  ∞0.210 1.5168 64.2 20  ∞ 0.512 (IM) ∞f123=5.474 mmf789=−4.636 mmf34=12.013 mmf89=−4.341 mmT7=0.295 mmT8=1.000 mmD34=0.122 mmD89=0.564 mmTL=7.095 mmHmax=4.70 mmDep=2.691 mm

TABLE 12 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 12.946E−02 −2.714E−03 −1.663E−03  1.164E−03 −1.063E−03  3.450E−044.733E−05 −4.035E−05 2 0.000E+00 −1.957E−02  2.723E−02 −1.951E−026.623E−03 −6.604E−04  2.511E−05 −7.123E−05 3 −5.839E+00  −3.870E−02 3.291E−02 −2.135E−02 5.769E−03 2.302E−03 −1.690E−03   2.073E−04 4−9.739E+00   2.270E−02 −2.310E−02  1.561E−02 −7.769E−03  3.249E−034.927E−04 −4.662E−04 5 0.000E+00 −1.393E−02 −9.645E−03  4.740E−03−9.169E−03  6.106E−03 7.070E−04 −7.182E−04 6 0.000E+00 −3.558E−02−1.704E−02  5.769E−04 2.046E−03 4.568E−04 5.238E−04 −2.333E−04 70.000E+00 −3.276E−02 −1.534E−02  5.282E−03 5.902E−04 4.955E−04 1.797E−04−7.400E−05 8 0.000E+00 −3.589E−02 −1.470E−02  1.726E−03 2.110E−036.595E−05 −3.257E−04   4.101E−05 9 0.000E+00 −1.900E−02 −2.978E−02−2.230E−05 7.977E−04 1.059E−03 4.053E−04 −3.408E−04 10 0.000E+00−5.611E−02 −1.782E−02  9.837E−04 2.856E−03 2.208E−04 −1.599E−04  2.123E−05 11 0.000E+00 −8.870E−02 −6.648E−03  7.392E−03 1.008E−031.828E−04 5.633E−05 −7.355E−05 12 0.000E+00 −4.340E−02  8.197E−03 1.530E−06 4.304E−04 5.629E−05 −1.277E−05  −1.226E−05 13 1.521E+00−3.148E−02  3.184E−02 −1.607E−02 5.257E−03 −1.002E−03  9.886E−05−2.277E−06 14 −1.006E+01  −2.125E−02  1.839E−02 −1.124E−02 3.647E−03−5.119E−04  2.410E−05  3.378E−07 15 5.888E−01  2.643E−02 −1.390E−02−1.547E−04 4.010E−04 −1.090E−04  2.996E−05 −3.164E−06 16 0.000E+00 1.322E−02 −2.609E−03 −6.865E−04 1.924E−04 −1.341E−05  6.665E−10 2.146E−08 17 9.633E+00 −7.878E−02  1.805E−02 −2.255E−03 2.128E−04−1.505E−05  6.425E−07 −1.204E−08 18 −4.676E+00  −5.183E−02  1.450E−02−2.883E−03 3.595E−04 −2.626E−05  1.026E−06 −1.656E−08

The values of the respective conditional expressions are as follows:f123/f=0.925f3/f2=−1.005D34/f=0.021T8/T7=3.390D89/f=0.095R9r/f=0.420f9/f=−0.795f4/f|=25.106TL/f=1.198TL/Hmax=1.510f/Dep=2.20f6/f=3.149

Accordingly, the imaging lens of Numerical Data Example 6 satisfies theabove-described conditional expressions.

FIG. 17 shows a lateral aberration that corresponds to an image height Hand FIG. 18 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 17 and 18 , according tothe imaging lens of Numerical Data Example 6, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 7

Basic Lens Data

TABLE 13 f = 6.29 mm Fno = 1.8 ω = 35.7° i r d n d ν d [mm] ∞ ∞ L1   1*(ST) 2.557 0.589 1.5443 55.9 f1 = 8.116  2* 5.578 0.029 L2  3*2.204 0.240 1.6707 19.2 f2 = −10.017  4* 1.587 0.127 L3  5* 2.816 0.7191.5348 55.7 f3 = 6.372  6* 14.774 0.109 L4  7* 77.735 0.309 1.5348 55.7f4 = 88.615  8* −121.242 0.253 L5  9* −17.339 0.269 1.5348 55.7 f5 =−113.722 10* −24.385 0.283 L6 11* −4.878 0.332 1.6707 19.2 f6 = 95.60612* −4.657 0.152 L7 13* −5.946 0.530 1.6707 19.2 f7 = −27.537 14* −9.0840.028 L8 15* 4.252 0.513 1.5443 55.9 f8 = 26.601 16* 5.765 0.674 L9 17*3.815 0.560 1.5348 55.7 f9 = −8.670 18* 1.986 0.250 19  ∞ 0.210 1.516864.2 20  ∞ 1.006 (IM) ∞f123=5.754 mmf789=−8.764 mmf34=5.992 mmf89=−15.099 mmT7=0.530 mmT8=0.513 mmD34=0.109 mmD89=0.674 mmTL=7.112 mmHmax=4.52 mmDep=3.500 mm

TABLE 14 Aspherical surface data i k A4 A6 A8 A10 1 −5.244E−01  9.466E−03  1.227E−03 −1.104E−03   2.574E−04 2 0.000E+00  4.755E−02−6.466E−02 9.079E−02 −1.008E−01 3 −8.611E+00   4.915E−02 −7.643E−029.652E−02 −1.052E−01 4 −2.198E+00  −5.844E−02  8.105E−02 −1.096E−01  1.085E−01 5 −5.321E+00   4.650E−03  6.470E−02 −1.541E−01   2.241E−01 60.000E+00 −2.384E−02 −3.105E−03 4.734E−02 −9.335E−02 7 0.000E+00−3.190E−02  8.567E−03 1.997E−03 −3.927E−03 8 0.000E+00 −1.865E−02 3.579E−04 1.417E−03 −2.441E−03 9 0.000E+00 −4.421E−02 −1.153E−026.774E−03 −6.488E−03 10 0.000E+00 −2.313E−02 −1.891E−02 5.601E−03 3.530E−03 11 0.000E+00  3.512E−02 −7.096E−02 4.637E−02 −9.606E−03 120.000E+00  3.168E−02 −3.088E−02 −1.752E−02   3.186E−02 13 0.000E+00 1.090E−02  2.830E−02 −4.919E−02   2.598E−02 14 0.000E+00 −8.373E−04 3.882E−03 −1.863E−03  −4.251E−04 15 3.943E−01  3.787E−03 −3.884E−021.660E−02 −4.833E−03 16 0.000E+00  2.095E−02 −2.722E−02 7.606E−03−9.417E−04 17 −1.621E−01  −1.233E−01  4.013E−02 −8.446E−03   9.161E−0418 −7.422E+00  −5.250E−02  1.360E−02 −2.593E−03   3.123E−04 i A12 A14A16 A18 A20 1  2.533E−05 −7.997E−06 −1.764E−06  4.415E−07 −2.733E−07  2 7.465E−02 −3.519E−02  1.017E−02 −1.647E−03 1.147E−04 3  7.849E−02−3.721E−02  1.077E−02 −1.738E−03 1.208E−04 4 −7.485E−02  3.385E−02−9.267E−03  1.395E−03 −8.907E−05  5 −2.006E−01  1.105E−01 −3.621E−02 6.500E−03 −4.902E−04  6  9.985E−02 −6.256E−02  2.284E−02 −4.492E−033.707E−04 7  4.699E−04  6.901E−04 −2.373E−05 −1.681E−04 4.234E−05 8−1.569E−04  7.916E−04  1.617E−04 −2.770E−04 6.381E−05 9  6.002E−03−4.621E−04 −1.428E−03  6.665E−04 −1.027E−04  10 −7.544E−04 −4.275E−04 1.165E−04  1.144E−04 −5.283E−05  11 −1.841E−02  2.181E−02 −1.205E−02 3.689E−03 −5.023E−04  12 −2.123E−02  4.814E−03  1.641E−03 −1.037E−031.452E−04 13 −5.280E−03 −3.073E−03  2.829E−03 −8.435E−04 8.794E−05 14 2.133E−04  3.526E−05 −2.093E−05  1.743E−06 5.867E−08 15  1.182E−03−2.158E−04  1.313E−05  2.262E−06 −2.687E−07  16 −1.395E−05  1.489E−05−7.460E−07 −8.368E−08 7.047E−09 17 −2.374E−05 −2.385E−06 −1.088E−07 3.230E−08 −1.112E−09  18 −2.271E−05  9.662E−07 −2.042E−08 −2.592E−113.951E−12

The values of the respective conditional expressions are as follows:f123/f=0.915f3/f2=−0.636D34/f=0.017T8/T7=0.968D89/f=0.107R9r/f=0.316f9/f=−1.378|f4/f|=14.088TL/f=1.131TL/Hmax=1.573f/Dep=1.80f8/f=4.229

Accordingly, the imaging lens of Numerical Data Example 7 satisfies theabove-described conditional expressions.

FIG. 20 shows a lateral aberration that corresponds to an image height Hand FIG. 21 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 20 and 21 , according tothe imaging lens of Numerical Data Example 7, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 8

Basic Lens Data

TABLE 15 f = 5.80 mm Fno = 2.2 ω = 39.0° i r d n d ν d [mm] ∞ ∞ L1  1*2.653 0.662 1.5443 55.9 f1 = 5.163    2*(ST) 43.434 0.040 L2  3* 4.1810.276 1.6707 19.2 f2 = −12.667  4* 2.728 0.423 L3  5* 14.680 0.5471.5443 55.9 f3 = 12.902  6* −13.286 0.129 L4  7* −12.003 0.375 1.544355.9 f4 = 79.377  8* −9.497 0.206 L5  9* −13.718 0.265 1.5443 55.9 f5 =−100.330 10* −18.445 0.050 L6 11* −15.366 0.321 1.5443 55.9 f6 = 13.92412* −5.113 0.073 L7 13* −3.881 0.265 1.6707 19.2 f7 = 100.690 14* −4.2310.196 L8 15* −12.893 0.800 1.5443 55.9 f8 = −60.884 16* −21.566 0.535 L917* 62.744 0.765 1.5443 55.9 f9 = −4.896 18* 2.546 0.300 19  ∞ 0.2101.5168 64.2 20  ∞ 0.522 (IM) ∞f123=5.270 mmf789=−4.027 mmf34=11.269 mmf89=−4.373 mmT7=0.265 mmT8=0.800 mmD34=0.129 mmD89=0.535 mmTL=6.887 mmHmax=4.70 mmDep=2.636 mm

TABLE 16 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 12.946E−02 −2.563E−03 −1.649E−03  1.166E−03 −1.044E−03  3.209E−046.070E−05 −3.576E−05 2 0.000E+00 −1.994E−02  2.742E−02 −1.928E−026.640E−03 −6.688E−04  3.147E−05 −7.009E−05 3 −5.839E+00  −4.125E−02 3.256E−02 −2.154E−02 5.737E−03 2.367E−03 −1.680E−03   2.128E−04 4−9.739E+00   1.933E−02 −2.544E−02  1.551E−02 −7.622E−03  3.276E−035.081E−04 −3.735E−04 5 0.000E+00 −1.056E−02 −8.155E−03  5.716E−03−8.530E−03  6.370E−03 7.315E−04 −7.880E−04 6 0.000E+00 −2.912E−02−1.542E−02  1.420E−03 2.190E−03 4.396E−04 5.134E−04 −2.169E−04 70.000E+00 −3.577E−02 −1.505E−02  4.866E−03 3.375E−04 4.119E−04 1.732E−04−5.290E−05 8 0.000E+00 −3.882E−02 −1.580E−02  1.465E−03 2.086E−038.218E−05 −3.368E−04   2.193E−05 9 0.000E+00 −1.852E−02 −3.462E−02−9.709E−04 6.087E−04 9.767E−04 3.618E−04 −3.647E−04 10 0.000E+00−5.683E−02 −1.822E−02  6.578E−04 2.707E−03 1.797E−04 −1.608E−04  3.077E−05 11 0.000E+00 −8.870E−02 −6.111E−03  7.671E−03 1.063E−031.757E−04 4.485E−05 −7.992E−05 12 0.000E+00 −4.020E−02  8.729E−03−2.971E−05 4.499E−04 6.343E−05 −1.129E−05  −1.281E−05 13 1.521E+00−2.949E−02  3.226E−02 −1.597E−02 5.268E−03 −1.002E−03  9.800E−05−2.626E−06 14 −1.006E+01  −2.214E−02  1.842E−02 −1.123E−02 3.650E−03−5.106E−04  2.445E−05  3.469E−07 15 5.888E−01  2.378E−02 −1.322E−02−3.466E−05 4.148E−04 −1.056E−04  3.079E−05 −3.031E−06 16 0.000E+00 1.172E−02 −2.451E−03 −6.775E−04 1.926E−04 −1.343E−05  −4.784E−09  2.064E−08 17 9.633E+00 −7.846E−02  1.807E−02 −2.255E−03 2.127E−04−1.506E−05  6.413E−07 −1.215E−08 18 −4.676E+00  −5.069E−02  1.433E−02−2.879E−03 3.597E−04 −2.626E−05  1.026E−06 −1.657E−08

The values of the respective conditional expressions are as follows:f123/f=0.909f3/f2=−1.019D34/f=0.022T8/T7=3.019D89/f=0.092R9r/f=0.439f9/f=−0.844f4/f|=13.686TL/f=1.187TL/Hmax=1.465f/Dep=2.20

Accordingly, the imaging lens of Numerical Data Example 8 satisfies theabove-described conditional expressions.

FIG. 23 shows a lateral aberration that corresponds to an image height Hand FIG. 24 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 23 and 24 , according tothe imaging lens of Numerical Data Example 8, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 9

Basic Lens Data

TABLE 17 f = 5.62 mm Fno = 1.9 ω = 38.8° i r d n d ν d [mm] ∞ ∞ L1  1*2.410 0.765 1.5443 55.9 f1 = 5.705    2*(ST) 9.557 0.050 L2  3* 3.8310.240 1.6707 19.2 f2 = −15.996  4* 2.752 0.379 L3  5* 12.093 0.3521.5443 55.9 f3 = 21.585  6* −407.953 0.161 L4  7* −32.648 0.400 1.544355.9 f4 = 20.671  8* −8.404 0.129 L5  9* −7.273 0.298 1.5443 55.9 f5 =−40.506 10* −11.011 0.168 L6 11* −3.433 0.412 1.6707 19.2 f6 = −20.74212* −4.777 0.080 L7 13* −34.551 0.641 1.5443 55.9 f7 = 8.678 14* −4.1830.026 L8 15* 5.706 0.645 1.5443 55.9 f8 = 52.687 16* 6.840 0.610 L9 17*826.452 0.601 1.5443 55.9 f9 = −4.987 18* 2.705 0.250 19  ∞ 0.210 1.516864.2 20  ∞ 0.691 (IM) ∞f123=6.145 mmf789=−56.237 mmf34=10.744 mmf89=−5.891 mmT7=0.641 mmT8=0.645 mmD34=0.161 mmD89=0.610 mmTL=7.037 mmHmax=4.52 mmDep=2.972 mm

TABLE 18 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 12.138E−01  2.437E−03 −4.046E−04  1.772E−03 −8.446E−04  2.477E−041.026E−05 −8.781E−06 2 0.000E+00 −2.041E−02  2.862E−02 −1.827E−027.056E−03 −1.221E−03  −9.036E−05   4.995E−05 3 −3.695E+00  −4.437E−02 3.194E−02 −1.688E−02 6.304E−03 −7.906E−04  −2.695E−04   1.157E−04 4−8.276E+00   1.695E−02 −1.258E−02  1.324E−02 −1.010E−02  9.186E−03−5.022E−03   1.338E−03 5 0.000E+00 −1.506E−02 −9.879E−03  5.220E−04−3.606E−03  2.341E−03 1.534E−03 −1.002E−03 6 0.000E+00 −2.466E−02−2.492E−02  1.184E−02 −2.937E−03  1.566E−03 1.699E−03 −9.831E−04 70.000E+00 −2.631E−02 −2.970E−02 −9.661E−05 1.067E−02 1.336E−03−3.554E−03   9.170E−04 8 0.000E+00  8.258E−03 −5.444E−02  4.873E−033.731E−03 2.331E−03 −2.213E−03   5.137E−04 9 0.000E+00  7.014E−03−5.507E−02  8.574E−03 −1.823E−03  1.028E−03 1.813E−03 −6.291E−04 100.000E+00 −2.811E−02 −1.703E−02  1.630E−03 1.654E−03 1.435E−04−7.561E−05  −4.622E−06 11 2.498E+00 −1.107E−02  2.425E−02 −9.932E−034.061E−03 −1.122E−03  1.659E−04 −8.125E−06 12 −5.224E+00  −4.191E−02 3.128E−02 −1.154E−02 3.023E−03 −6.081E−04  1.002E−04 −1.004E−05 130.000E+00 −8.188E−03  1.083E−02 −6.359E−03 1.041E−03 1.043E−04−8.669E−05   1.113E−05 14 0.000E+00  3.091E−02 −3.652E−03  4.085E−04−1.955E−04  9.988E−06 1.876E−06  8.842E−09 15 1.715E+00 −8.358E−03−5.354E−04 −2.437E−03 7.278E−04 −9.710E−05  7.374E−06 −2.555E−07 160.000E+00  1.034E−02 −4.258E−03 −2.632E−04 1.903E−04 −1.909E−05 2.464E−07  2.591E−08 17 0.000E+00 −5.151E−02  1.476E−02 −2.109E−032.187E−04 −1.610E−05  5.152E−07  2.342E−10 18 −5.107E+00  −4.630E−02 1.316E−02 −2.725E−03 3.514E−04 −2.629E−05  1.043E−06 −1.708E−08

The values of the respective conditional expressions are as follows:f123/f=1.093f3/f2=−1.349D34/f=0.029T8/T7=1.006D89/f=0.109R9r/f=0.481f9/f=−0.887|f4/f|=3.678TL/f=1.252TL/Hmax=1.557f/Dep=1.89

Accordingly, the imaging lens of Numerical Data Example 9 satisfies theabove-described conditional expressions.

FIG. 26 shows a lateral aberration that corresponds to an image height Hand FIG. 27 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 26 and 27 , according tothe imaging lens of Numerical Data Example 9, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 10

Basic Lens Data

TABLE 19 f = 6.22 mm Fno = 2.2 ω = 36.8° i r d n d ν d [mm] ∞ ∞ L1   1*(ST) 2.288 0.784 1.5443 55.9 f1 = 4.682  2* 19.734 0.017 L2  3*4.992 0.268 1.6707 19.2 f2 = −13.021  4* 3.108 0.488 L3  5* −574.6690.516 1.5443 55.9 f3 = 40.146  6* −21.058 0.091 L4  7* 40.931 0.3081.5443 55.9 f4 = 59.919  8* −160.079 0.254 L5  9* −28.959 0.777 1.544355.9 f5 = −99.665 10* −62.709 0.252 L6 11* −3.200 0.250 1.6707 19.2 f6 =−100.368 12* −3.466 0.030 L7 13* −9.478 0.318 1.5443 55.9 f7 = 16.38814* −4.650 0.032 L8 15* 19.516 0.350 1.5443 55.9 f8 = −95.037 16* 14.0800.718 L9 17* −326.264 0.766 1.5443 55.9 f9 = −5.589 18* 3.073 0.250 19 ∞ 0.210 1.5168 64.2 20  ∞ 0.509 (IM) ∞f123=5.847 mmf789=−8.686 mmf34=24.068 mmf89=−5.247 mmT7=0.318 mmT8=0.350 mmD34=0.091 mmD89=0.718 mmTL=7.118 mmHmax=4.65 mmDep=2.828 mm

TABLE 20 Aspherical surface data i k A4 A6 A8 A10 A12 A14 A16 17.617E−01 −1.117E−02 −3.100E−03 −3.298E−03 1.153E−03 −7.086E−04 1.133E−04 −2.825E−05  2 0.000E+00 −4.732E−02  4.539E−02 −2.827E−029.365E−03 −1.440E−03 −1.986E−04 8.128E−05 3 −3.214E+00  −3.582E−02 3.254E−02 −7.542E−03 −4.806E−04   1.416E−03 −7.776E−04 1.513E−04 4−3.351E+00   1.851E−02 −2.229E−02  4.911E−02 −4.604E−02   2.921E−02−1.053E−02 1.644E−03 5 0.000E+00 −7.044E−04 −4.908E−03 −2.532E−039.444E−03 −4.396E−03  1.225E−03 −4.012E−05  6 0.000E+00  1.574E−02−6.266E−02  4.182E−03 1.669E−02 −6.175E−03 −6.454E−06 2.911E−04 70.000E+00  2.514E−02 −8.054E−02  6.674E−03 2.243E−03  2.323E−03 1.185E−03 −8.064E−04  8 0.000E+00  2.149E−03 −2.464E−02 −1.504E−026.377E−03  5.560E−03 −3.124E−03 4.913E−04 9 0.000E+00 −1.090E−02−2.732E−02  3.262E−03 3.334E−03 −6.024E−03  3.770E−03 −8.069E−04  100.000E+00  1.357E−02 −1.628E−02  5.691E−03 −2.382E−03   1.288E−03−3.032E−04 2.645E−05 11 −3.141E+00  −1.167E−02  1.282E−02 −1.474E−03−3.892E−04   1.780E−04 −6.133E−05 7.719E−06 12 −7.659E+00  −3.136E−02 2.026E−02 −5.680E−03 1.577E−03 −3.746E−04  3.827E−05 −6.966E−07  130.000E+00  2.264E−03  4.503E−03 −3.788E−03 4.540E−04  1.700E−05 3.824E−06 −9.779E−07  14 0.000E+00  2.490E−02 −7.476E−03  3.145E−041.473E−04 −1.108E−05 −4.413E−07 1.509E−08 15 0.000E+00  2.502E−02−1.237E−02  1.332E−03 3.179E−04 −1.145E−04  1.372E−05 −6.601E−07  160.000E+00  6.130E−03 −2.313E−03 −3.997E−04 1.846E−04 −2.136E−05 6.259E−07 1.702E−08 17 0.000E+00 −5.661E−02  1.374E−02 −1.512E−035.397E−05  4.960E−06 −5.278E−07 1.271E−08 18 −6.607E+00  −3.655E−02 9.603E−03 −1.771E−03 2.129E−04 −1.584E−05  6.542E−07 1.140E−08

The values of the respective conditional expressions are as follows:f123/f=0.940f3/f2=−3.083D34/f=0.015T8/17=1.101D89/f=0.115R9r/f=0.494f9/f=−0.899|f4/f|=9.633TL/f=1.144TL/Hmax=1.531f/Dep=2.20

Accordingly, the imaging lens of Numerical Data Example 10 satisfies theabove-described conditional expressions.

FIG. 29 shows a lateral aberration that corresponds to an image height Hand FIG. 30 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 29 and 30 , according tothe imaging lens of Numerical Data Example 10, the aberrations can bealso satisfactorily corrected.

Numerical Data Example 11

Basic Lens Data

TABLE 21 f = 6.44 mm Fno = 1.8 ω = 35.0° i r d n d ν d [mm] ∞ ∞ L1   1*(ST) 2.542 0.601 1.5443 55.9 f1 = 7.987  2* 5.610 0.028 L2  3*2.214 0.240 1.6707 19.2 f2 = −9.799  4* 1.584 0.126 L3  5* 2.818 0.7311.5348 55.7 f3 = 6.315  6* 15.471 0.107 L4  7* 80.794 0.312 1.5348 55.7f4 = 91.684  8* −124.559 0.255 L5  9* −16.542 0.255 1.5348 55.7 f5 =104.625 10* −23.612 0.312 L6 11* −4.367 0.332 1.6707 19.2 f6 = −103.40712* −4.802 0.134 L7 13* −6.191 0.540 1.6707 19.2 f7 = −43.774 14* −8.1200.027 L8 15* 4.184 0.492 1.5443 55.9 f8 = 25.814 16* 5.711 0.691 L9 17*3.766 0.564 1.5348 55.7 f9 = −8.932 18* 1.996 0.250 19  ∞ 0.210 1.516864.2 20  ∞ 1.065 (IM) ∞f123=5.716 mmf789=−10.815 mmf34=5.954 mmf89=−16.190 mmT7=0.540 mmT8=0.492 mmD34=0.107 mmD89=0.691 mmTL=7.202 mmHmax=4.50 mmDep=3.480 mm

TABLE 22 Aspherical surface data i k A4 A6 A8 A10 1 −4.495E−01  1.125E−02 −2.451E−03 8.994E−04  7.060E−05 2 0.000E+00  4.381E−02−6.416E−02 9.226E−02 −1.009E−01 3 −9.709E+00   4.679E−02 −7.486E−029.684E−02 −1.052E−01 4 −2.763E+00  −5.585E−02  8.483E−02 −1.099E−01  1.081E−01 5 −5.844E+00  −7.475E−04  6.734E−02 −1.517E−01   2.244E−01 60.000E+00 −2.991E-02  −2.782E−03 5.153E−02 −9.481E−02 7 0.000E+00−4.259E−02  1.002E−02 1.713E−03 −2.821E−03 8 0.000E+00 −2.766E−02−1.154E−03 2.416E−03 −2.340E−03 9 0.000E+00 −5.345E−02 −9.331E−031.094E−02 −7.707E−03 10 0.000E+00 −2.910E−02 −3.649E−03 3.572E−03 2.817E−03 11 0.000E+00  3.287E−02 −5.927E−02 4.556E−02 −1.253E−02 120.000E+00  3.125E−02 −3.307E−02 −1.746E−02   3.314E−02 13 0.000E+00 1.274E−02  1.859E−02 −4.538E−02   2.613E−02 14 0.000E+00 −2.329E−03 3.466E−03 −1.204E−03  −2.950E−04 15 −6.104E−01  −4.147E−03 −3.292E−021.610E−02 −5.041E−03 16 0.000E+00  8.106E−03 −2.148E−02 6.570E−03−9.385E−04 17 −1.953E−01  −1.271E−01  4.032E−02 −8.490E−03   9.571E−0418 −7.322E+00  −5.473E−02  1.448E−02 −2.765E−03   3.306E−04 i A12 A14A16 A18 A20 1 −7.962E−05 1.656E−06  6.815E−06 6.414E−07 −8.765E−07 2 7.450E−02 −3.520E−02   1.018E−02 −1.642E−03   1.129E−04 3  7.839E−02−3.723E−02   1.078E−02 −1.731E−03   1.181E−04 4 −7.482E−02 3.392E−02−9.291E−03 1.373E−03 −8.048E−05 5 −2.011E−01 1.102E−01 −3.618E−026.551E−03 −5.039E−04 6  9.906E−02 −6.245E−02   2.299E−02 −4.510E−03  3.644E−04 7  2.566E−04 3.655E−04 −1.014E−05 −4.271E−05   1.149E−05 8 1.569E−04 1.099E−03  2.520E−05 −4.553E−04   1.339E−04 9  5.104E−03−5.208E−04  −1.516E−03 7.450E−04 −8.816E−05 10 −1.542E−03 −5.433E−04  1.410E−04 1.851E−04 −4.908E−05 11 −1.833E−02 2.224E−02 −1.202E−023.600E−03 −4.788E−04 12 −2.148E−02 4.576E−03  1.700E−03 −9.902E−04  1.299E−04 13 −5.156E−03 −3.024E−03   2.798E−03 −8.723E−04   9.654E−0514  1.644E−04 2.114E−05 −2.002E−05 2.776E−06 −5.947E−08 15  1.182E−03−2.130E−04   1.419E−05 2.444E−06 −3.221E−07 16 −3.725E−06 1.559E−05−8.526E−07 −1.058E−07   9.849E−09 17 −2.546E−05 −2.973E−06  −1.238E−073.810E−08 −1.074E−09 18 −2.301E−05 9.220E−07 −2.442E−08 2.937E−10 9.142E−12

The values of the respective conditional expressions are as follows:f123/f=0.888f3/f2=−0.644D34/f=0.017T8/T7=0.911D89/f=0.107R9r/f=0.310f9/f=−1.387|f4/f|=14.237TL/f=1.118TL/Hmax=1.600f/Dep=1.85f8/f=4.008

Accordingly, the imaging lens of Numerical Data Example 11 satisfies theabove-described conditional expressions.

FIG. 32 shows a lateral aberration that corresponds to an image height Hand FIG. 33 shows a spherical aberration (mm), astigmatism (mm), and adistortion (%), respectively. As shown in FIGS. 32 and 33 , according tothe imaging lens of Numerical Data Example 11, the aberrations can bealso satisfactorily corrected.

According to the embodiment of the invention, the imaging lenses havevery wide angles of view (2ω) of 65° or greater. According to theimaging lens of the embodiment, it is possible to take an image over awider range than that taken by a conventional imaging lens.

In recent years, with advancement in digital-zoom technology to enlargeany range of an image obtained through an imaging lens, an imagingelement with a higher pixel count has been more frequently applied incombination with an imaging lens of higher resolution. In many cases ofsuch an imaging element with a high pixel count, a light-receiving areaper pixel decreases, so that an image tends to be dark. According to theimaging lenses of the embodiment, it is achievable to take asufficiently bright image even with the above-described imaging elementwith a higher pixel count.

Accordingly, when the imaging lens of the above-described embodiment isapplied in an imaging optical system such as cameras built in mobiledevices (e.g., cellular phones, smartphones, and mobile informationterminals), digital still cameras, security cameras, onboard cameras,and network cameras, it is possible to attain both high performance anddownsizing of the cameras.

Accordingly, the present invention is applicable in an imaging lens thatis mounted in a relatively small-sized camera, such as cameras built inmobile devices (e.g., cellular phones, smartphones, and mobileinformation terminals), digital still cameras, security cameras, onboardcameras, and network cameras, it is possible to attain both highperformance and downsizing of the cameras.

The disclosure of Japanese Patent Application No. 2018-248774, filed onDec. 29, 2019, is incorporated in the application by reference.

While the present invention has been explained with reference to thespecific embodiment of the present invention, the explanation isillustrative and the present invention is limited only by the appendedclaims.

What is claimed is:
 1. An imaging lens comprising: a first lens; asecond lens; a third lens; a fourth lens; a fifth lens; a seventh lens;an eighth lens; and a ninth lens having negative refractive power,arranged in this order from an object side to an image plane side,wherein said imaging lens has a total of nine lenses, said first lens isformed in a shape so that a surface thereof on the image plane side hasan aspherical shape, and said ninth lens is formed in a shape so that asurface thereof on the image plane side has an aspherical shape.
 2. Theimaging lens according to claim 1, wherein said first lens, said secondlens, and said third lens have a composite focal length f123 so that thefollowing conditional expression is satisfied:0.5<f123/f<2.5, where f is a focal length of a whole lens system.
 3. Theimaging lens according to claim 1, wherein said seventh lens, saideighth lens, and said ninth lens have a composite focal length f789 sothat the following conditional expression is satisfied:f789<0.
 4. The imaging lens according to claim 1, wherein said secondlens has a focal length f2, and said third lens has a focal length f3 sothat the following conditional expression is satisfied:−6<f3/f2<−0.2.
 5. The imaging lens according to claim 1, wherein saidseventh lens has a thickness T7 near an optical axis thereof, and saideighth lens has a thickness T8 near an optical axis thereof so that thefollowing conditional expression is satisfied:0.5<T8/T7<4.
 6. The imaging lens according to claim 1, wherein saidninth lens is formed in the shape so that the surface thereof on theimage plane side has a paraxial curvature radius R9r so that thefollowing conditional expression is satisfied:0.2<R9r/f<0.6, where f is a focal length of a whole lens system.
 7. Theimaging lens according to claim 1, wherein said ninth lens has a focallength f9 so that the following conditional expression is satisfied:−2<f9/f<−0.2, where f is a focal length of a whole lens system.
 8. Animaging lens comprising: a first lens; a second lens; a third lens; afourth lens; a fifth lens; a sixth lens; a seventh lens; an eighth lens;and a ninth lens having negative refractive power, arranged in thisorder from an object side to an image plane side, wherein said imaginglens has a total of nine lenses, said eighth lens has at least oneaspheric surface, said ninth lens is formed in a shape so that a surfacethereof on the image plane side has an aspherical shape, and saidseventh lens, said eighth lens, and said ninth lens have a compositefocal length f789 so that the following conditional expression issatisfied:f789<0.
 9. The imaging lens according to claim 8, wherein said firstlens, said second lens, and said third lens have a composite focallength f123 so that the following conditional expression is satisfied:0.5<f123/f<2.5, where f is a focal length of a whole lens system. 10.The imaging lens according to claim 8, wherein said second lens has afocal length f2, and said third lens has a focal length f3 so that thefollowing conditional expression is satisfied:−6<f3/f2<−0.2.
 11. The imaging lens according to claim 8, wherein saidseventh lens has a thickness T7 near an optical axis thereof, and saideighth lens has a thickness T8 near an optical axis thereof so that thefollowing conditional expression is satisfied: 0.5<T8/T7<4.
 12. Theimaging lens according to claim 8, wherein said ninth lens is formed inthe shape so that the surface thereof on the image plane side has aparaxial curvature radius R9r so that the following conditionalexpression is satisfied:0.2<R9r/f<0.6, where f is a focal length of a whole lens system.
 13. Theimaging lens according to claim 8, wherein said ninth lens has a focallength f9 so that the following conditional expression is satisfied:−2<f9/f<−0.2, where f is a focal length of a whole lens system.
 14. Animaging lens comprising: a first lens; a second lens; a third lens; afourth lens; a fifth lens; a sixth lens; a seventh lens; an eighth lens;and a ninth lens having negative refractive power, arranged in thisorder from an object side to an image plane side, wherein said imaginglens has a total of nine lenses, said eighth lens has at least oneaspheric surface, said ninth lens is formed in a shape so that a surfacethereof on the image plane side has an aspherical shape, and saidseventh lens has a thickness T7 near an optical axis thereof, and saideighth lens has a thickness T8 near an optical axis thereof so that thefollowing conditional expression is satisfied:0.5<T8/T7<4.
 15. The imaging lens according to claim 14, wherein saidfirst lens, said second lens, and said third lens have a composite focallength f123 so that the following conditional expression is satisfied:0.5<f123/f<2.5, where f is a focal length of a whole lens system. 16.The imaging lens according to claim 14, wherein said seventh lens, saideighth lens, and said ninth lens have a composite focal length f789 sothat the following conditional expression is satisfied:f789<0.
 17. The imaging lens according to claim 14, wherein said secondlens has a focal length f2, and said third lens has a focal length f3 sothat the following conditional expression is satisfied:−6<f3/f2<−0.2.
 18. The imaging lens according to claim 14, wherein saidninth lens is formed in the shape so that the surface thereof on theimage plane side has a paraxial curvature radius R9r so that thefollowing conditional expression is satisfied:0.2<R9r/f<0.6, where f is a focal length of a whole lens system.
 19. Theimaging lens according to claim 14, wherein said ninth lens has a focallength f9 so that the following conditional expression is satisfied:−2<f9/f<−0.2, where f is a focal length of a whole lens system.
 20. Theimaging lens according to claim 14, wherein said first lens has anAbbe's number νd1 so that the following conditional expression issatisfied:35<νd1<80.